Host plants of the pale mottled willow Paradrina clavipalpis (Scop.) (Lepidoptera: Noctuidae)

2007·1.5 MB·English

by  A H Dobson

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268 BR.J.ENT.NAT.HIST.,20:2007
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Host plants ofthe Pale Mottled Willow Pavadrina clavipalpis (Scop.) (Lepidoptera:
Noctuidae). -With reference to Len Winokur’s communication (2007) about finding
a larva of P. clavipalpis within a spun leaf of goat willow Salix caprea, near
Winchester (VC 12), one needs to decide whether it is a realistic food plant or not.
The Victorian, Edwardian and pre-war II lepidopterists, not having the
advantages of ultra-violet light to find species, had to rely mainly on fieldwork.
Scorer(1913) listed Poaceae (grasses), Pisum (pea) and seeds ofPlantago (plantains).
Allan (1949), a renowned fieldworker and author, listed Plantago spp., Stellaria
media (chickweed), Triticum vulgare (wheat), on the grains and Pisum sativum (field
pea), on the seeds. I have beaten and searched Salix at a number ofsites in VC 1
and 12 (Dobson, 1989) where P. clavipalpis imagines have occurred at light, but
neverfoundthelarvae on bushesortrees. I thinkitisevidentthat P. clavipalpisisnot
arboreal and that Salixis notits food plantand that itis simply a ‘tourist’ i.e. a non-
predatory species thathas no lastingassociationwith theplant, butmay be attracted
for shelter, sun-basking or sexual display (Moran & Southwood, 1982).
I have witnessed, though rarely, other species exhibiting apparently unusual
behaviour. One example was ofthe copper underwing Amphipyrapyramidea (L.) an
arboreal species; I found a larva feeding on prostrate Cotoneaster horizontalis in a
garden far removed from shrubs and trees at Sparsholt College (VC 11). The most
puzzling host association occurred in April 1964, when I collected a disused song
thrush’s nest, which was 1 m up in a thick hedge at Cullompton (VC 3). In school,
the children in my class carefully dismantled the nest to discoverits composition. To
our surprise there was a noctuid pupa within the base. I retained the pupa and on
24.V.1964 an adult clouded-bordered brindle Apamea crenata (Hufn.) emerged. This
species, like P. clavipalpis is also a ground level feeding species, firstly on the flowers
and immature seeds ofPoaceae and later on the foliage; the pupa is in a loose cell
spun amongst the roots ofgrasses (Emmet & Heath, 1983). Perhaps the reason for
thelarva spinningin thebird’snestwasthatitscomposition appearedlikea tangleof
roots. A clue for the clavipalpis larva’s behaviour might be wood; it has been stated
‘the pupa is in a tough cocoon ofsilk and other available material such as abraded
wood and vegetable debris (ibid. p. 281). Was the larva attracted to the base ofSalix
by its woody stem? Why did both individual larvae climb up from ground level?
Perhaps both were escaping adverse conditions on the ground.
I have experienced larvae ofP. clavipalpis feeding well above the ground, because
ofhuman activity. On 5.i.l990 I answered a request for help by visiting Mr. & Mrs.
Frith’s cottage in Chestnut Avenue, Eastleigh (VC 11). They were being inundated
by numerous larvae dropping from the thatch and falling down the chimneys. The
cottage had been re-thatched the previous year with wheat reed on which, I
presumed, many ova oftheculprit, P. clavipalpis, had been laid. BarryGoater(1974)
stated that, ‘itwas frequent in towns . . . and throughout the agricultural belt, where
the larvae could be a minor pest in grain stacks and in growing wheat at harvest
(CHD); the larva probably also feeds on wild grasses in chalk pasture.’ C.H. Dixon
lived at Northbridge Farm, Micheldever just under seven kilometres from where
Winokur’s larva was found. Changes in agricultural practices have removed this
species from wheat and pea crops grown there and elsewhere.
I do agree with Len Winokur that S. caprea is a popular food plant for
Lepidoptera. In an unpublished paper (1984) producedforthe localWild LifeTrust,
I compiled a list offood plants ofLepidoptera found in North Hampshire (VC 12)
and the number oflarval species perplant to show the relative importance ofcertain
BR.J.ENT.NAT.HIST.,20;2007 269
plants to Lepidoptera, as a guide for conservation. The compilation was based on
Lepidoptera species listed in Goater (1974), but excluding species with fewer than
five specimens recorded and non-breeding migrant species. Food plants were listed
from my experience and the literature: Scorer (1913), Stokoe (1948), Allan (1949),
Emmet (1988) and Emmet and Heath (1979 & 1983). Top ofthe list for host trees
were S. caprea (goat willow) and Quercus spp. (deciduous oaks), with 180 species
each, followed by Betula spp. (birch) 175, and Crataegus spp. (hawthorns) 150. -
A.H. Dobson, 282 Britten Road, Basingstoke RG22 4HR.-,
References
Allan, P.B.M. 1949. Larvalfoodplants, London: Watkins & Doncaster.
Dobson,A.H. 1984.A listofwildfoodplantsfortheLepidoptera (butterfliesandmothsincluding
Microlepidoptera)found in VC 12 North Hampshire and the number oflarval speciesper
plant. Unpublished report.
Dobson, A.H. 1989. Lepidoptera food plant recording for conservation. British Journal of
Entomology & NaturalHistory, 2: 131-138.
Emmet, A.M. (Ed.) 1988. Afieldguide to the smaller British Lepidoptera, 2nd Edn, London:
BENHS.
Emmet, A.M. & Heath, J. (Eds) 1979. The moths andbutterflies ofGreat Britain AndIreland.
London: Curwen Books.
Emmet, A.M. & Heath, J. (Eds) 1983. The moths andbutterflies ofGreat Britain andIreland.
Colchester: Harley Books, Vol. 10.
Goater, B. 1974. ThebutterfliesandmothsofHampshireandtheIsleofWight. Faringdon: E.W.
Classey Ltd.
Moran, V.C. & Southwood, T.R.E. 1982. Theguildcomposition ofarthropodcommunitiesin
trees. JournalofAnimalEcology, 51: 289-306.
Scorer, A.G. 1913. The entomologist’s logbook anddictionary ofthe lifehistories ofthe British
Macrolepidoptera, London: Routledge.
Stokoe, W.H. 1948. Caterpillars ofBritish moths, series 1 & 2, London: Warne.
Winokur, L. 2007. Pale mottled willow Paradrina clavipalpis larva on Salix caprea. British
JournalofEntomology & NaturalHistory, 20: 138.
Holcostethus vernalis (Wolff) (Hem.: Pentatomidae) and Bathysolen nubilis (Fallen)
(Hem.: Coreidae) inHampshire. -On 29 May 2007, I swept an adult male H.vernalis
from a rough grassy glade in an abandoned orchard in Lock’s Heath, South
Hampshire (VCll) (SU5006). This appears to be the first record of this species in
Hampshire (Bernard Nau,pers. comm?}, and my second coming after another single
male from the former Ore Power Station, Hastings, East Sussex (TQ8210) on 22
September 2003.
On 4 June 2007, I visited part of the old Royal Aircraft Establishment at
Farnborough, North Hampshire (VC12) (SU8654), where a large area of black
medick Medicago lupulinahaddeveloped on foundations ofa buildingdemolishedin
2002. Having found B. nubilus in similar places in Essex and Kent in recent years, I
was unsurprised to find adults under the first rosette examined. These appear to be
the first seen in Hampshire, and a westerly extension to its known range, lying some
35km from Surbiton, where I found it new for Surrey in 1998. Jonty Denton, 29
Yarnhams Close, Four Marks, Hants, GU34 SDH.